The present invention relates in general to a method for providing dimensionally corrected and functionally enhanced parts to manufacturers, and in particular to a method for enabling manufacturers to select from a plurality of options as to the materials and methods used in dimensionally correcting and functionally enhancing the parts.
Millions of parts for machines, equipment, devices, apparatus and products are manufactured or machined every day around the world. Such parts are made out of metals, plastics and a variety of other materials. People have developed and refined various manufacturing methods for producing such parts. However, despite the continued advancements in the manufacturing and machining arts, mass manufacturing machine processes are generally not one hundred percent accurate. The specifications for such parts therefore incorporate tolerances (i.e., the desired dimension plus or minus some acceptable amount) as is well understood in the art.
For example, the manufacturer of a bushing may include in the bushing specifications an aperture having a diameter of 0.50+/xe2x88x920.005 inches. This means that the diameter of the aperture of the bushing must be anywhere between 0.495 inches to 0.505 inches to be within specifications and acceptable to the end user of the bushing. If the diameter of the aperture of the bushing is not within these specifications, the bushing cannot be used without correction.
During the typical manufacturing processes, there is a statistically normal dimensional distribution of parts around a specified value as illustrated by the bell curve in FIG. 1. This bell curve represents the normal dimensional distribution of parts around the desired value, where DOTS (i.e., dimensional optimum target specification) represents the desired value, LSL (i.e., lower specification limit) represents a first or lower dimensional limit and USL (i.e., upper specification limit) represents a second or upper dimensional limit. If the bell curve represented the distribution of bushings in the example provided above, DOTS would represent the desired aperture diameter of 0.50 inches, LSL would represent a first dimensional limit defined as bushings having an aperture diameter of 0.495 inches (i.e., 0.50 inchesxe2x88x920.005 inches) and USL would represent the second dimensional limit defined as the bushing having an aperture diameter of 0.505 inches (i.e., 0.50 inches plus 0.005 inches). Any parts which have an aperture diameter less than the first dimensional limit LSL or exceeding the second dimensional limit USL cannot be used without correction. Those parts which have an aperture diameter that fall within the range defined by dimensional limits LSL and USL are generally usable by the manufacturer in this example.
Those parts that fall outside the range defined by dimensional limits LSL and USL are out of range, out of specification and are not usable without dimensional correction. Ordinarily, this means that these parts must either be salvaged (if possible) or discarded by the manufacturer. Generally, if the part having a dimension smaller than the LSL is going to be salvaged or further processed, the part must be dimensionally enlarged, further machined, honed, reamed or ballsized (i.e., making the aperture diameter larger and closer to the DOTS). It has been well known to, and manufacturers often, dimensionally change a part with a coating. However, the process of making an aperture of a part smaller is generally expensive and time-consuming and therefore not readily undertaken by manufacturers.
The manufacturing process is often complicated because the part, a surface of the part or an aperture in the part may need to have a functionally enhanced surface and still remain within the specifications. The functionally enhanced surface may be a low friction surface provided by a coating, lining, bonded material, lubricant, sealing, or other similar material such as a fluoropolymer such as PTFE (Teflon(copyright)), referred to herein for brevity as enhancing functional material (as opposed to painting or plating). The enhanced surface may also be a high friction surface provided by an adhesive or other bonded material.
Current technology only enables these parts to be measured after the added material is cured, rigid or firm. Conventional wet film thickness testing gauges tend to damage the material in a measuring process because they puncture the material while it is wet. Thus, a manufacturer may produce, through conventional spray coating, thousands of parts during a run, only to find upon final inspection that they are out-of-range, out-of-specification, and cannot be used by the manufacturer or their customers without further correction and expense.
Further additional material generally can not be added to a cured undersized previously enhanced aperture. The material must be stripped before a greater amount of material can be attached to the part. Stripping fluoropolymer or other functional materials is extremely tedious, exacting and generally not economically feasible. Moreover, even if the material is easily removed from the parts, the part must be re-processed and recoated. This process is labor, material and time intensive which is cost prohibitive and inhibits just-in-time delivery. Further, some materials like fluoropolymer resins cannot be easily stripped once they are cured. Stripping the fluoropolymer resin may generate gases which are currently under study by entities who believe there is a high element of toxicity in over-cured or thermally-degraded fluoropolymer and other organic materials or coatings.
Manufacturers must address the above issues in an coordinated efficient manner. Accordingly, there is a need for a method for providing dimensionally corrected and functionally enhanced parts to manufacturers which accounts for the level and extent the manufacturer desires to have its parts simultaneously corrected and/or enhanced in compliance with both the dimensional specifications and the other functional requirements for the parts.
The method of the present invention provides manufacturers a plurality of options for and enables manufacturers to select how the manufacturers desire their parts to be measured, dimensionally corrected and functionally enhanced. For purposes of this application xe2x80x9cmanufacturerxe2x80x9d includes manufacturers, suppliers, distributors, vendors, purchasers and assemblers of parts and their customers. The method generally includes: (i) offering the manufacturer a plurality of options for dimensionally correcting and functionally enhancing the manufacturers"" raw parts; (ii) having the manufacturer select or provide the dimensions of the raw parts to correct and enhance from a population of raw parts provided by the manufacturer, select one or more portions or surfaces of each raw part to be dimensionally corrected and/or functionally enhanced, and select at least one or more materials to be used for dimensionally correcting and/or functionally enhancing the part; (iii) having the manufacturer provide the parts to the implementor of the method; (iv) dimensionally correcting and functionally enhancing such selected parts in accordance with the manufacturers"" individually selected options; and (v) providing the dimensionally corrected and functionally enhanced parts to the manufacturer. Preferably, if possible, the implementor simultaneously dimensionally corrects and functionally alters the parts.
The first and second steps include a plurality of sub-options or selections for the manufacturer. For example, the manufacturer can select all the raw parts in a population of raw parts for enhancing or select only those raw parts that fall within a predetermined dimensional range. The manufacturer can also select the entire raw part for enhancing, a portion of the raw part, one surface of the raw part or multiple surfaces. The manufacturer is also provided with a number of options with regard to the materials to be used for enhancing and the number of layers of the materials.
It is therefore an object of the present invention to provide a method for providing dimensionally corrected and functionally enhanced parts to manufacturers.
A further object of the present invention is to provide manufacturers with a plurality of options for dimensionally correcting and functionally enhancing raw parts.
A further object of the present invention is to provide manufacturers with a plurality of options for selecting the parts, the portion of the parts and the materials to be used in dimensionally correcting and functionally enhancing raw parts.
Other objects, features and advantages of the invention will be apparent from the following detailed disclosure, taken in conjunction with the accompanying sheets of drawings, wherein like numerals refer to like parts, components and steps.